EP1976697B1 - Method for producing a cladding element - Google Patents

Abstract

Method for producing a cladding element. The method includes applying a resin to a visible surface and to a contact surface of a wood material base board, applying at least one non-resin impregnated paper ply to the visible surface and at least one non-resin impregnated paper ply to the contact surface of the wood material base board, and pressing the at least one non-resin impregnated paper ply onto the resin applied visible surface and the at least one non-resin impregnated paper ply onto the resin applied contact surface. In this manner, the at least one paper ply on the visible surface and at least one paper ply on the contact surface are fully impregnated.

Description

The invention relates to a method for producing a cladding element, for example a floor panel, a wall cladding element, a furniture front panel or the like, wherein the cladding element comprises a base plate having on a surface, namely its visible surface or their contact surface opposite the viewing surface, with a resin-impregnated paper layer is provided.

Such methods are well known in the art. Such a method is to be described below with reference to Fig. 2 be explained in more detail. However, it should already be stated at this point that the method of the prior art described below with respect to the materials used does not differ from the method according to the invention. All statements of material made with reference to the known method as well as information on other parameters such as layer thicknesses, grammages and the like therefore also apply equally to the method according to the invention.

Both the known method, the method steps in Fig. 2 are shown schematically, as well as the inventive method to be discussed later, the production of a cladding element 10 to the goal, as shown in Fig. 3 is shown:

The cladding element 10 comprises a base plate 12, which is preferably formed from a wood material, for example a chipboard or a fiberboard, such as an MDF (Medium Density Fiberboard) or HDF (High Density Fiberboard) board. If the trim element is used as a floor panel, it preferably has a thickness of about 5 mm to about 15 mm.

On its visible surface 12 a, the base plate 12 is provided with a decorative paper layer 14 which comprises at least one decorative paper layer 16. On its visible surface 14a, the decorative paper layer 14 or its uppermost decorative paper layer 16 is printed with a desired decor, for example a wood, stone, tile or similar materials or products imitating decor. The paper used for the decorative paper layer 14 usually has a total grammage of about 45 g / m ² to about 160 g / m ² .

Such decorative papers are impregnated or impregnated with impregnating resin on special impregnating machines, which is described in US Pat Fig. 3 dotted is indicated. The amount of impregnating resin applied, based on the raw paper weight of the decorative paper layer 14, is about 100% to about 140%.

In order to be able to prevent deformation of the lining element 10 due to the tensions arising from the decorative paper layer 14, for example to a curvature which destroys its desired completely planar and planar shape, it can optionally be disposed opposite to that of the visible surface 12a of the base plate 12 Rear surface 12b of the base plate 12 a Gegenzugpapierlage 18 may be arranged. The Gegenzugpapierlage 18 is impregnated with impregnating resin, as in Fig. 3 indicated by the punctuation. With respect to the base paper weight, ie, the grammage of the paper used and the amount of impregnating resin applied, the countertransfer paper layer 18 substantially corresponds to the decor paper layer 14 to ensure that both paper layers 14 and 18 exert substantially canceling stresses on the base plate 12.

In order to protect the decorative paper layer 14 against abrasion, which is important not only when using the cladding element 10 as a floor panel, but also in its use as a wall cladding element or furniture front panel, may optionally also on the visible surface 14a of the decorative paper layer 14 nor a cover paper layer 20 (in the jargon also Overlay paper layer called) applied. Conventional cover papers or overlay papers preferably have a raw paper weight of about 10 g / m ² to about 80 g / m ² and are thus, especially when impregnated with impregnating resin, transparent, so as not to look at the decor of the decorative paper layer 14 to hinder. Based on the raw paper weight, the amount of impregnating resin is between about 100% and about 300%. To increase the abrasion resistance, the impregnating resin for the cover paper layer 20 may further be admixed with a suitable additive, for example corundum, preferably in an amount of about 5 g / m ² to about 50 g / m ² .

As impregnating resins, preference is given to using aminoplast resins, for example urea resins or melamine resins or mixtures of urea and melamine resins, melamine resin preferably being used to impregnate the cover paper layer 20.

The known method for producing such a cladding element 10, whose individual process steps schematically in Fig. 2 are shown, is aligned with the timing of the preparation of the base plate 12. Therefore, all papers used in the layer structure of the cladding element 10 must be kept in temporary storage so that there is no delay in the feed of the base plates 12 during production.

In a step D, for example, a decor paper 14 printed with a desired decor is provided. This is impregnated in a step DI in a special impregnating machine with impregnating resin. In this case, the impregnating resin can be applied in one or more stages on the decorative paper 14, penetrate into this and then dried. The decorative paper 14 thus impregnated is then formatted in a further step DF, ie cut to a size matched to the size of the supplied base plates 12. The decor paper 14 is now for further processing, especially the hot pressing with the base plate 12, finished and is fed in a step DL an intermediate storage 22, where it remains until further processing.

In an analogous manner, also the Gegenzugpapier 18 and the cover paper 20 in the step D corresponding steps R and O supplied as raw paper, in the step DI corresponding steps RI and OI impregnated with impregnating resin, in step DF corresponding steps RF and OF formatted and in Step DL corresponding steps RL and OL the intermediate storage 22 corresponding intermediate bearings 24 and 26, respectively.

If a base plate 12 is now conveyed in a step B, an impregnated and formatted decor paper 14, withdrawal paper 18 and cover paper 20 are removed from the associated intermediate storage 22, 24 and 26 in steps DS, RS and OS and in the above with reference to Fig. 3 described sequence stacked on each other. Subsequently, in a step HP, this stack is fed to a hot press 28, in which the paper layers 14, 18 and 20 are pressed with the base plate 12 to form the desired end product, namely the lining element 10, using an elevated pressure and temperature.

Although the hot press 28 in Fig. 2 roughly schematically in the form of two press plates, ie in the form of a stationary press, is indicated, it is understood that equally well as continuous or quasi-continuous presses, for example, continuous presses can be used.

The known method has the disadvantage that the papers impregnated with impregnating resin have only a limited shelf life. Namely, the impregnating resin must not already be thoroughly dried before hot pressing, but may only be so dry that the individual paper layers in the intermediate storage, for example, the Interim storage 22 for decorative paper 14, do not adhere to each other. In the interim storage the papers, in particular the impregnating resin with which they are impregnated, dry on, however, so that they reach a degree of drying when the storage time is too long, which does not permit proper hot pressing. Impregnated papers stored for too long must therefore be sorted out and disposed of, which is disadvantageous not least because of the high material costs for the aminoplast resins commonly used for impregnation.

WO 97/17214 A discloses a method for producing a cladding element with a base plate, on the visible surface of which a decorative layer is arranged, and the rear side of which carries a counteracting layer. In a mold, a resin molded body reinforced by a chipboard is manufactured together with decorative sheets. The decorative layers are placed in the mold, after which the mold is filled with liquid resin and the cladding element is finally produced as a resin molding in the mold.

To illustrate the technical background can also on the EP 0 745 478 A2 be referred, which describes the coating of an endless web material, namely a Linoleumbahn, wherein on a coated with liquid paint Linoleumbahn a paper layer is rolled on.

It is an object of the present invention to provide a method of the type mentioned, with which reduces the waste, if not completely avoided.

This object is achieved by a method according to claim 1.

According to the paper layer is thus not already impregnated with resin before the intermediate storage, but it is with the on the base plate applied resin brought into contact only during pressing of paper layer and base plate and thereby impregnated by the resin. The actual impregnation of the paper layer thus takes place only during pressing. The paper can therefore be stored as raw paper so that it is no longer subject to any time restrictions with regard to the intermediate storage time. In the case of the decorative paper layer, raw paper is also understood to mean paper already printed with a décor. Since the resin is applied to the base plate according to the invention, it is also ensured that resin is always consumed only when a base plate is actually available for further processing. The resin can be applied to the visible surface and / or the contact surface, for example, with a basis weight of between about 50 g / m ² and about 200 g / m ² . The order can be done for example by means of a known roller applicator.

A curing agent required for hardening hardener can be applied in a further development of the invention in the first step together with the resin on the surface of the base plate, preferably as a resin-hardener mixture. Alternatively, it is also possible and even advantageous if the hardener and the resin are applied in two separate steps on the surface of the base plate. Namely, the hardener is preferably applied to the surface of the base plate separately from the resin in a fourth step preceding the first step. By the latter method variant can also be circumvented the problem that a once mixed with the hardener resin within a predetermined processing time, also called pot life, must be processed. This leads to a further reduction of the risk of material scrap and thus contributes to a reduction in the manufacturing cost of the cladding elements.

As a hardener, for example, an ammonium chloride solution or an ammonium sulfate solution or a maleic anhydride solution can be used.

As is known per se from the prior art, in the method according to the invention the paper layer can also be formatted in a fifth step preceding the second step, the difference to the prior art method being merely that the paper layer is in the base paper layer is formatted.

Depending on the desired structure of the cladding element to be produced, only a decorative paper layer can be applied to the visible surface of the base plate by the method according to the invention. in the With regard to the deformation problem explained at the outset, it is optionally also possible to provide a counterweight paper layer on the contact surface of the base plate.

The base plate is provided both on its visible surface and on its contact surface each with a paper layer, namely a decorative paper layer on the visible surface and a Gegenzugpapierlage on the contact surface. In a further development of the invention, it is advantageous to save time when the first steps of applying the respective resin to the respective surface and / or the second steps of applying the respective paper layer to the respective surface provided with resin substantially simultaneously.

In addition, with regard to the abrasion or abrasion problem explained above, it is optionally also possible to provide a cover paper layer on the visible side of the base plate above the decorative paper layer. In this case, the amount of resin applied to the visible surface of the base plate in the first step may preferably be such that it is sufficient for impregnating both the decorative paper layer and the cover paper layer during the pressing of the paper layers with the base plate in the third method step.

Moreover, when the base plate is provided on its visible surface with both a decorative paper layer and a cover paper layer, the second steps of applying the two paper layers to the resinous visible surface of the base plate and / or the third steps of pressing the two Make paper layers with the base plate substantially simultaneously.

As already mentioned, the resin may be an aminoplast resin, preferably a urea resin or a melamine resin or a urea resin-melamine resin mixture. Furthermore, the resin, in particular the for Impregnating the visible surface provided paper layers used resin, at least one abrasion resistance increasing substance, such as corundum, included.

It should be added that each of the paper layers, i. the decorative paper layer and / or the Gegenzugpapierlage and / or the cover paper layer may be formed by a plurality of paper layers.

If desired, the cladding element produced in this way can be supplied to a surface finish. For this purpose, the surface of the decorative paper layer or optionally the surface of the cover paper layer is first subjected to a surface treatment. This surface treatment may comprise a chemical treatment, for example the application of an adhesion promoter and / or a fluorination, and / or a mechanical treatment, for example surface grinding, and / or electrical treatment, for example corona treatment and / or plasma treatment. On the surface prepared in this way, a lacquer layer can then be applied and dried. If desired, this paint application can also be repeated several times, if necessary, with renewed previous surface treatment of the last applied paint layer.

Suitable adhesion promoters include, for example, the product sold by Henelit, Villach, Austria "Hydrohaftgrund E643" or organofunctional silane. Organofunctional silanes are hybrid compounds having a reactive organic group and an inorganic alkyl silicate, in which both the organic functional group and the inorganic hydrolyzable alkoxy group can be tailored to the impregnating resin or aminoplast resin used and the lacquer used in order to achieve good adhesion-promoting properties.

During fluorination, the resin-impregnated decorative paper layer pressed with the base plate can be treated in a vacuum reactor. After evacuation and inerting the reactor, ie removing any impurities still adhered or bound to reactor surfaces, for example by inert gas flushing, heating the reactor or the like, fluorine and inert gas are selectively added using a variable concentration profile of the fluorine mixture at ambient temperature during the treatment time can for best results. Thereafter, the reactor is evacuated, rinsed and the decorative paper layer can be removed. This so-called offline fluorination can be integrated as a post-treatment method in every production process. Due to the fluorination, the surface tension and thus the wetting of the surface is improved by a paint. In addition, a polar surface is achieved, which leads to better adhesion of a paint layer.

In a corona treatment, air that is in the space between two electrodes is ionized. These ions then penetrate depending on their kinetic energy in the surface of the arranged between the electrodes to be treated decorative paper layer, for example, up to 10 microns deep. The resulting physical and chemical changes on the surface of the treated decorative paper layer can not yet be clearly explained. It is assumed, however, that oxidation processes at the surface play a role as well as physical and chemical changes of the surface caused by the bombardment with accelerated ions and electrons. However, it is a scientifically proven fact that corona treatment causes improved surface adhesion such that, as desired, a coated lacquer layer will adhere better to a decorative paper sheet so treated.

Similar effects are also achieved with the plasma treatment, in which case the direct electrical arc which is produced at the electrodes subjected to high voltage is not used for the treatment of the surface, but instead a reactive, potential-free particle beam by means of charge separation ionized air generated and is directed to the surface of the decorative paper sheet to be treated.

By appropriate polishing of the thus treated, in particular painted surface, any desired surface reflection property can be achieved in a simple manner from matt gloss to high gloss. Especially with highly polished surface is a panel element whose decorative paper layer is printed with a wood decor, practically indistinguishable from real wood.

Fig. 1

ein schematisches Ablaufdiagramm einer Ausführungsvariante des erfindungsgemäßen Verfahrens;

Fig. 2

eine Ansicht ähnlich Fig. 1 eines Herstellungsverfahrens nach dem Stand der Technik; und

Fig. 3

eine schematische Darstellung zur Erläuterung des Schichtaufbaus eines nach dem erfindungsgemäßen Verfahren herzustellenden Verkleidungselements.

The invention will be explained in more detail below with reference to the accompanying drawings of an embodiment. It shows:

Fig. 1

a schematic flow diagram of an embodiment of the method according to the invention;

Fig. 2

a view similar Fig. 1 a manufacturing method according to the prior art; and

Fig. 3

a schematic representation for explaining the layer structure of a produced by the process according to the invention cladding element.

Regarding Fig. 1 In the following, a method according to the invention for producing a cladding element 10 will be explained in more detail, which has already been described in the introduction with reference to FIG Fig. 3 has explained structure, that is provided in particular on its visible surface 12a both with a decorative paper layer 14 and with a cover paper layer 20, and at its contact surface 12b with a Gegenzugpapierlage 18.

As in Fig. 1 illustrated, the decorative paper layer 14 is provided in a step D as raw paper and formatted in a step DF in a size matching the dimensions of the base plate 12 size. In a step DL The formatted decorative paper ply 14 is then fed to a buffer store 22, in which it is temporarily stored until further processing.

Analogously, in the step D corresponding steps R and O provided as base paper Gegenzugpapierlagen 18 or cover paper layers 20 in the step DF corresponding steps RF or OF formatted in the step DL corresponding steps RL or OL a buffer 24 and 26 supplied. In contrast to the method of the prior art explained in the introduction, the papers intermediately stored in the intermediate buffers 22, 24 and 26 are therefore not impregnated with resin. This eliminates the problem occurring in the known method that must be taken into account by the drying time of the resin, maximum intermediate storage times, completely.

In the method according to the invention, a base plate 12 provided in a step B is provided in a step BID on its visible surface 12a with a layer of impregnating resin, more precisely with a layer of a impregnating resin-hardener mixture. If necessary, the base plate 12 may also be rear-side, i. be provided on its contact surface 12b, in a step BIR with a corresponding layer.

Alternatively, the steps BID and BIR can each also be divided into two temporally spaced steps BHD and BAD or BHR and BAR, which in Fig. 1 indicated by dashed arrows. In steps BHD and BHR, a hardener required for curing the impregnating resin is first applied to the visible surface 12a or the rear surface 12b of the base plate 12, and then the actual application of the impregnating resin takes place in the steps BAD and BAR. The latter method variant is advantageous in view of the problem of the pot life of an impregnating resin-hardener mixture.

The steps BID and BIR or the steps BHD and BHR and the steps BAD and BAR may preferably be made substantially simultaneously.

The base plate 12 thus coated with resin on its two surfaces 12a, 12b is fed to a stacking process in step BS, in which a decorative paper layer 14 supplied in step DS to the visible surface 12a of the base plate 12 and optionally a cover paper layer 20 fed in a step OS is placed as well as optionally optionally on the contact surface 12b of the base plate 12, a fed in a feed step RS Gegenzugpapierlage 18 is placed. The stack thus formed is fed in a step HP a hot press 28, in which the various paper layers are pressed under increased pressure and elevated temperature with the base plate 12. In particular, during this pressing operation, the resin applied to the base plate 12 penetrates into the various paper layers and impregnates or impregnates them. This gives a cladding element 10 with the in Fig. 3 layer structure shown.

If desired, the cladding element 10 produced in this way can then be subjected to a surface refinement. For this purpose, the surface 14a of the decorative paper layer or optionally the surface 20a of the cover paper layer 20 is first subjected to a surface treatment. This surface treatment may comprise a chemical treatment, for example the application of an adhesion promoter and / or a fluorination, and / or a mechanical treatment, for example surface grinding, and / or electrical treatment, for example corona treatment and / or plasma treatment. On the surface prepared in this way can then be applied and dried a lacquer layer 30, the in Fig. 3 only indicated by dashed lines. If desired, this paint application can also be repeated several times, if necessary with prior surface treatment of the last applied paint layer.

According to one embodiment, the surface treatment initially comprises the application of an adhesion promoter, for example of the product sold by the company Henelit, Villach, Austria "Hydrohaftgrund E643", in an amount of between about 5 g / m ² and about 30 g / m ² . This bonding agent is then cured by means of UV radiation. To further improve the adhesion of the subsequent coating application, the surface can then be sanded, if desired, even. The paint can be applied as a roller paint or spray paint. For example, a polyurethane varnish or a UV varnish can be used as the varnish, for example the "UV Hydro Brilliant" varnish marketed by the company Henelit, Villach, Austria. The paint application can be carried out in an amount of between about 15 g / m ² and about 30 g / m ² for the paint base layer and between about 5 g / m ² and about 10 g / m ² for other paint layers.

To increase the abrasion resistance of the paint layer, the paint may be admixed with a suitable additive, for example corundum, preferably in an amount of about 5 g / m ² to about 50 g / m ² . If the abrasion resistance of the lacquer layer applied in this way is sufficient, the use of a cover paper can be dispensed with. Since the lacquer layer does not lead to any additional stress in the layer structure applied to the visible surface 12a of the base plate 12, no special precautions need to be taken on the rear surface 12b of the base plate 12 in the countertraction paper layer 18.

Claims (17)

1. A method for producing a cladding element (10), for example a flooring panel, a wall cladding element, a furniture face element or the like, wherein the cladding element (10) comprises a base board (12) which on two surfaces, namely its visible surface (12a) and its contact surface (12b) opposite the visible surface, is provided with a respective paper layer (14,18) impregnated with resin,
   wherein in a first step (BID,BIR) the resin is applied to the surfaces (12a,12b) of the base board (12), in a second step (DS,RS) following in time the first step (BID,BIR) the paper layers (14,18) are applied to the surfaces (12a,12b) of the base board (12), and in a third step (HP) following in time the second step (DS,RS) the base board (12) provided with resin and the two paper layers (14,18) are pressed together substantially simultaneously,
   wherein both paper layers (14,18) are impregnated with the resin only in the third step (HP).
2. A method according to Claim 1,
   characterised in that a hardener necessary for hardening the resin in the first step (BID,BIR) is applied jointly with the resin to the surface (12a,12b) of the base board (12), preferably as a resin-hardener mixture.
3. A method according to Claim 1,
   characterised in that a hardener necessary for hardening the resin is applied separately from the resin to the surface (12a,12b) of the base board (12), preferably in a fourth step preceding in time the first step (BID, BIR) .
4. A method according to any one of Claims 1 to 3,
   characterised in that the paper layer (14,18) is formatted in a fifth step preceding in time the second step (DS,RS).
5. A method according to any one of Claims 1 to 4,
   characterised in that the first steps (BID,BIR) of applying the respective resin to the respective surface (12a,12b) and/or the second steps (DS,RS) of applying the respective paper layer (14,18) to the respective surface (12a,12b) provided with resin are carried out substantially simultaneously.
6. A method according to any one of Claims 1 to 5,
   characterised in that if the base board (12) is provided on its visible surface (12a) both with a decorative paper layer (14) and with a covering paper layer (20), in the first step (BID) an amount of resin is applied to the visible surface (12a) of the base board (12) which is measured taking into account both paper layers (14,20).
7. A method according to any one of Claims 1 to 6,
   characterised in that if the base board (12) is provided on its visible surface (12a) both with a decorative paper layer (14) and with a covering paper layer (20), the second steps (DS,OS) of applying the two paper layers (14,20) to the visible surface (12a) of the base board (12) provided with resin and/or the third steps (HP) of pressing the two paper layers (14,20) with the base board (12) are carried out substantially simultaneously.
8. A method according to any one of Claims 1 to 7,
   characterised in that the resin is an amino resin, preferably a urea-formaldehyde resin or a melamine resin or a urea-formaldehyde melamine resin mixture.
9. A method according to any one of Claims 1 to 8,
   characterised in that the resin contains at least one substance increasing abrasion resistance, for example corundum.
10. A method according to the preamble of Claim 1 and, if desired, the characterising part of any one of Claims 1 to 9,
    characterised in that a visible surface (14a,20a) of the decorative paper layer or of the covering paper layer (20) is firstly subjected to at least one surface treatment, and in that at least one varnish layer (30) is then applied to this treated surface.
11. A method according to Claim 10,
    characterised in that the at least one surface treatment comprises a chemical treatment.
12. A method according to Claim 11,
    characterised in that the at least one surface treatment comprises the application of an adhesion promoter, for example of organofunctional silane, or a fluorination.
13. A method according to any one of Claims 10 to 12,
    characterised in that the at least one surface treatment comprises an electrical treatment.
14. A method according to Claim 13,
    characterised in that the at least one surface treatment comprises a corona treatment or a plasma treatment.
15. A method according to any one of Claims 10 to 14, characterised in that the at least one surface treatment comprises a mechanical treatment.
16. A method according to Claim 15,
    characterised in that the at least one surface treatment comprises a grinding of the surface.
17. A method according to any one of Claims 10 to 16, characterised in that the varnish contains at least one substance increasing abrasion resistance, for example corundum.

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